Integral double rod spinal construct

ABSTRACT

An integral dual rod spinal construct for immobilizing and stabilizing vertebral bodies of the spine is described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a Continuation of International Pat. App. No.PCT/US17/18898, filed Feb. 22, 2017 (pending). International Pat. App.No. PCT/US17/18898, claims the priority of U.S. Provisional ApplicationNo. 62/298,279, filed on Feb. 22, 2016, the entire disclosure of whichis incorporated herein by reference.

BACKGROUND

Field of the Disclosure

The present disclosure relates generally to medical devices, morespecifically spinal rods for immobilizing and stabilizing vertebralbodies of the spine.

Background

The spine is formed of a column of vertebra that extends between thecranium and pelvis. The three major sections of the spine are known asthe cervical, thoracic and lumbar regions. There are 7 cervicalvertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae, with each ofthe 24 vertebrae being separated from each other by an intervertebraldisc. A series of about 9 fused vertebrae extend from the lumbar regionof the spine and make up the pelvic region of the vertebral column.These fused vertebrae consist of the sacral and coccygeal region of thevertebral column.

The main functions of the spine are to provide support and protect thespinal cord. Even slight disruptions to either the intervertebral discsor vertebrae can result in serious discomfort due to decompression ofnerve fibers either within the spinal cord or extending from the spinalcord. If a disruption to the spine becomes severe enough, damage to anerve or part of the spinal cord may occur and can result in partial tototal loss of bodily functions (e.g. walking, talking, and breathing).

Each year millions of people suffer from back pain arising from defectsin the intervertebral disc space. Commonly, surgical interventionsdirected at promoting fusion across the affected joint are employed topermanently provide long term pain relief to the patient. Typically,such fusion surgeries involve performing a partial or completediscectomy to prepare the disc space, and then implanting a natural orsynthetic intervertebral fusion implant within the prepared disc space.

Surgical procedures on the spine (for example, procedures meant to fusetwo or more vertebra together) often include the immobilization of twoor more vertebra. Immobilizing the vertebrae may be accomplished in manyways (e.g. fixation plates and pedicle screw systems). One of the mostcommon methods for achieving the desired immobilization is through theapplication of bone anchors (most often introduced into the pediclesassociated with the respective vertebra to be fixed) that are thenconnected by rigid rods locked to each pedicle screw. Pedicle screwsgenerally include an anchor component and a rod-housing component (or“tulip”) that is often coupled to the anchor component in a manner thatpermits angular adjustability of the tulip relative to the anchorcomponent in one or more planes. Once the pedicle screws are implantedin the desired positions a spinal rod is seated in each tulip and lockedin position.

One complication of spinal surgery is failure of the implantedcomponents. Rod failure can occur where rod strength is compromisedduring bending of the rods to fit patient anatomy, or where the stressloads placed on the rod are too great. Therefore, in some proceduresthat are known to introduce higher stress to the implanted rod, such aspedicle subtraction osteotomy (PSO), it may be desirable to provideincreased strength to the rod to increase stability and support toprevent negative outcomes that can result from rod failure.

It is desirable that an improved rod increase the stiffness and fatiguestrength of the construct while having a minimal effect on the ease withwhich the construct is implanted and/or the amount of hardware needed toenhance the strength of the construct (e.g. in comparison to currenttechniques employing multiple side-by-side rods connected by a series ofconnectors). An improved rod as disclosed herein could be used forincreased stability of short or long constructs, trauma, or posteriorreconstruction, in support of spinal fusion. For example, the improvedrod disclosed herein may help reduce the incidence of rod fractureacross a PSO or unstable construct.

SUMMARY

The needs above, as well as others, are addressed by embodiments of adual rod spinal fixation constructs described in this disclosure.

In a first aspect, a spinal fixation construct is disclosed comprising:a first spinal rod; a second spinal rod generally parallel to the firstrod; a cephalad arm connecting the first and second rods and integrallyformed with the first and second rods; and a caudal arm connecting thefirst and second rods and integrally formed with the first and secondrods.

In a second aspect, a spinal rod fixation construct is disclosedcomprising: a dual rod formed as a single unit, a plurality of boneanchors with upstanding arms defining a rod channel, and a plurality oflock screws.

In a third aspect, a dual spinal rod for fixing the relative position ofa first vertebra and a second vertebra is disclosed, the dual spinal rodcomprising: a first elongate member of generally cylindrical shapehaving a first cephalad end and a first caudal end, the first elongatemember being of a diameter suitable to be seated within a rod channel ofa pedicle screw, and being of a length sufficient to connect twoadjacent vertebrae; a second elongate member roughly parallel to thefirst elongate member having a second cephalad end and a second caudalend; a cephalad lateral portion connecting the first cephalad end to thesecond cephalad end; and a caudal lateral portion connecting the firstcaudal end to the second caudal end and roughly parallel to the cephaladlateral portion; wherein the dual spinal rod is constructed entirelyfrom a rigid, non-absorbable biocompatible material.

In a fourth aspect, a dual spinal rod for fixing the relative positionof a first vertebra and a second vertebra is disclosed, the dual spinalrod comprising: a first elongate member of generally cylindrical shapebeing of a diameter suitable to be seated within a rod channel of apedicle screw, and being of a length sufficient to connect two adjacentvertebrae; a second elongate member roughly parallel to the firstelongate member having a cephalad end and a caudal end; a cephaladlateral portion connecting the cephalad end of the second elongatemember to the first elongate member; and a caudal lateral portionconnecting the caudal end of the second elongate member to the firstelongate member, and roughly parallel to the cephalad lateral portion;wherein the dual spinal rod is constructed entirely from a rigid,non-absorbable biocompatible material; wherein the first elongateportion extends beyond a point at which it connects to the cephaladlateral portion in a longitudinal direction; and wherein the firstelongate portion extends beyond a point at which it connects to thecaudal lateral portion in the longitudinal direction.

In a fifth aspect, a method of stabilizing vertebra in a spinalprocedure a disclosed, the method comprising: implanting a plurality ofbone anchors; seating the first rod of the spinal rod fixation constructin the rod housing of the plurality of bone anchors; and engaging aplurality of lock screws complementary to the bone anchors such that thelock screws secure the spinal rod fixation construct in the rod housingof the plurality of bone anchors.

The above presents a simplified summary in order to provide a basicunderstanding of some aspects of the claimed subject matter. Thissummary is not an extensive overview. It is not intended to identify keyor critical elements or to delineate the scope of the claimed subjectmatter. Its sole purpose is to present some concepts in a simplifiedform as a prelude to the more detailed description that is presentedlater.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of one example of an integral double rodspinal construct.

FIG. 2 is a top plan view of the integral double rod spinal construct ofFIG. 1.

FIG. 3 is a perspective view of a second embodiment of an integraldouble rod spinal construct.

FIG. 4 is a top plan view of the integral double rod spinal construct ofFIG. 3.

FIG. 5 is a perspective view of a third embodiment of an integral doublerod spinal construct.

FIG. 6 is a top plan view of the integral double rod spinal construct ofFIG. 5.

DETAILED DESCRIPTION

Illustrative embodiments of a system for spinal fixation, parts, andmethods for use thereof, are described below. In the interest ofclarity, not all features of an actual implementation are described inthis specification. It will of course be appreciated that in thedevelopment of any such actual embodiment, numerousimplementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which will vary from one implementation toanother. Moreover, it will be appreciated that such a development effortmight be complex and time-consuming, but would nevertheless be a routineundertaking for those of ordinary skill in the art having the benefit ofthis disclosure. The system for spinal fixation, parts, and methods foruse thereof disclosed herein boasts a variety of inventive features andcomponents that warrant patent protection, both individually and incombination.

This disclosure describes several examples of an integral double rodspinal fixation construct suitable for use in spinal fixationprocedures. It will be appreciated that the spinal rod fixationconstruct disclosed may extend any number of levels from a single levelconstruct to a long construct spanning multiple spinal levels andmultiple spinal regions from the lumbosacral to cervical regions, andmay include any variety of combinations of known anchors, rods andconnectors.

By way of example, an integral double rod construct may be particularlybeneficial in procedures that introduce higher stress to the implantedrod, such as pedicle subtraction osteotomy (PSO). The integral doublerod spinal fixation construct of the present disclosure has severaladvantages over the prior art osteotomy systems. For example, integratedarms joining the rods may provide for a stiffer construct than acollection of single rods with added connectors, which may lead to lessrod failure in PSO. Placement of a single integral double rod is easier,faster, and cheaper than placing four single rods in parallel.Additionally, a construct comprising two rods instead of four rodsdecreases the metal and material through the fusion bed due to theelimination of two rods and multiple connectors.

A general embodiment of the construct comprises a first spinal rod, asecond spinal rod generally parallel to the first rod, and arms at eachend formed integrally with, and connecting the first and second rods.The components in the system are constructed from one or morenon-absorbable biocompatible materials. Specific examples of suchsuitable materials include titanium, alloys of titanium, steel, andstainless steel.

While this description refers to “first” and “second”, it will beappreciated that such terminology is provided to aid in distinguishingthe elements of the rods from one another and should not be read tolimit the claims to a particular order or orientation of the dual rod.

In an first general embodiment, a dual spinal rod 2 for fixing therelative position of a first vertebra and a second vertebra comprises afirst elongate member of generally cylindrical shape having a cephaladend and a caudal end. In some embodiments, the elongate member may be afirst rod 8. The first elongate member may have a diameter suitable tobe seated within a rod channel 22 of a pedicle screw. Further, theelongate member may be of a length sufficient to connect two adjacentvertebrae. The dual spinal rod further comprises a second elongatemember roughly parallel to the first elongate member. The secondelongate member may be a second rod 10. A cephalad lateral portionconnects the first and second elongate members at the cephalad end and acaudal lateral portion connects the first and second elongate members atthe caudal end. The lateral portion may be an arm 12. The caudal lateralportion is roughly parallel to the cephalad lateral portion. The dualspinal rod is constructed entirely from a rigid, non-absorbablebiocompatible material.

In a second general embodiment, a dual spinal rod 2 for fixing therelative position of a first vertebra and a second vertebra comprises afirst elongate member of generally cylindrical and having a diametersuitable to be seated within a rod channel 22 of a pedicle screw. Thefirst elongate member may be a first rod 8. The first elongate member isof a length sufficient to connect two adjacent vertebrae. The dual rodfurther comprises a second elongate member roughly parallel to the firstelongate member. The second elongate member may be a rod 10. Theelongate members are connected at their cephalad end and a caudal endsby lateral portions which are roughly parallel to one another. Thelateral portions may be arms 12. In some embodiments, the first elongateportion extends beyond a point at which it connects to the cephaladlateral portion in a longitudinal direction. In other embodiments, thefirst elongate portion extends beyond a point at which it connects tothe caudal lateral portion in the longitudinal direction. In yet furtherembodiments, elongate portions extend longitudinally beyond both thecephalad and caudal lateral portions. In each embodiment, the dualspinal rod is constructed entirely from a rigid, non-absorbablebiocompatible material.

More specifically, FIGS. 1-2 illustrate one example of an integraldouble rod spinal fixation construct 2 according to a first embodiment.When implanted in a patient, the rod spinal fixation construct 2 will beoriented in a generally cephalad-caudal orientation. The integral doublerod spinal fixation system includes an integral double spinal rod 4 anda plurality of bone anchors 6. The integral double spinal rod 4 includesa first rod 8 and a second rod 10 that is parallel to the first rod 8.The first and second rods 8, 10 are connected to each other at thecephalad and caudal ends by an arm 12 that is integrally formed with thefirst and second rods 8, 10 such that the first and second rods 8, 10and arms 12 comprise one single piece of metal. By way of example, thefirst and second rods 8, 10 and arms 12 may be of uniform thickness. Thefirst rod 8 is configured to engage the bone anchors 6 and is thereforegenerally cylindrical in shape. The second rod 10 may have anycross-sectional shape, and primarily functions to provide stability andrigidity to the construct, however the second rod portion 10 may also beused as an attachment point for additional hardware or for bending.

The bone anchor 6 may be any bone anchor suitable for use in a fixationprocedure, including without limitation bone screws or hooks. By way ofexample, the bone anchor 6 may be a polyaxial pedicle screw as shown inthe embodiment of FIG. 1. The bone anchor 6 of the current exampleincludes a shank 14 and a rod-housing 16 coupled to the shank. The shank14 has a threaded region 18 for purchase into the bone (e.g. a pedicle),a neck, and a head having a spherical undersurface and a drive toolengaging feature. The housing 16 includes a base and a pair ofupstanding arms extending from the base parallel to a longitudinal axisof the base. Slots separating the upstanding arms define a rod channel22 passing through the housing. The arms include tooling attachmentfeatures for coupling the housing to various tools useful duringimplantation of the bone anchor and associated fixation construct (e.g.inserters, reducers, etc. . . . ) and locking cap engagement featuresthat cooperate with a locking cap to capture and lock the first rod 8 inthe rod channel 22. The base includes a perimeter wall that defines aninner cavity configured to receive the shank head therein and a lowersurface with an opening into the inner cavity.

In use after the osteotomy procedure has progressed to the point wherebone has been removed and the surgeon needs to stabilize the spine, thefirst step is to implant the bone anchors 6 into the desired places onthe remaining bony structure. The integral double rod 4 is then placedin position by seating the first rod 8 in the rod housing 16 of the boneanchor 6. The integral double rod 4 may be placed such that the secondrod 10 is oriented either medially or laterally of the first rod 8. Anybending of the rod construct 2 that is necessary to have the first rod 8seat properly would occur at this time. A unique rod bender (not shown)may be provided that is capable of bending both rods 8, 10 at the sametime and to the same degree. After the integral double rod 4 has beenproperly placed, it is locked into position by engaging a plurality oflock screws with the housings 16 of the bone anchors 6.

FIGS. 3-4 illustrate an example of an integral double rod spinalfixation system 2 according to a second embodiment. The integral doublerod spinal fixation system includes an integral double spinal rod 20 anda plurality of bone anchors 6. The integral double spinal rod 20 of thesecond example includes a first rod 8 and a second rod 10 that isparallel to the first rod 8. The first and second rods 8, 10 areconnected to each other by an arm 12 that is integrally formed with thefirst and second rods 8, 10 such that the first and second rods 8, 10and arms 12 comprise one single piece of metal. By way of example, thearms 12 are located at each end of the second rod 10 and extendlaterally to connect with the first rod 8. By way of example, the firstand second rods 8, 10 and arms 12 may be of uniform thickness. The firstrod 8 is configured to engage the bone anchors 6 and is thereforegenerally cylindrical in shape. The first rod 8 further includes rodextensions 28 extending longitudinally from either end of the first rod8. The rod extensions 28 enable connection to additional hardware inlonger spine stabilization constructs, for example larger deformity ortrauma cases. The second rod 10 may have any cross-sectional shape, andprimarily functions to provide stability and rigidity to the construct,however the second rod 10 may also be used as an attachment point foradditional hardware or for bending, etc.

FIGS. 5-6 illustrate an example of an integral double rod spinalfixation system 2 according to a third embodiment. The integral doublerod spinal fixation system of the present example includes an integraldouble spinal rod 30 and a plurality of bone anchors 6. The integraldouble spinal rod 30 of the second example includes a first rod 8 and asecond rod 10 that is parallel to the first rod 8. The first and secondrods 8, 10 are connected to each other by an arm 12 that is integrallyformed with the first and second rods 8, 10 such that the first andsecond rods 8, 10 and arms 12 comprise one single piece of metal. By wayof example, the arms 12 are located at each end of the second rod 10 andextend laterally to connect with the first rod 8. By way of example, thefirst and second rods 8, 10 and arms 12 may be of uniform thickness. Thefirst rod 8 is configured to engage the bone anchors 6 and is thereforegenerally cylindrical in shape. The first rod 8 further includesintegrated rod connectors 38 positioned on either end of the first rod8. By way of example only, the integrated rod connectors 38 each includea rod seat 40 configured to receive at least a portion of a differentspinal rod. The integrated rod connectors 38 may be any type ofconnectors suitable for connecting to additional rod hardware. Theintegrated rod connectors 38 may be in-line or offset relative to thefirst rod 8. In some embodiments, the integrated rod connectors 38 maybe in-line with the second rod 10. The integrated rod connectors 38 maybe a top loading tulip configuration as shown by way of example in FIGS.5 & 6, or alternatively may be a side loading tulip or a closed headconnector of the adjacent rod. Thus the integrated rod connectors 38enable connection to additional hardware in longer spine stabilizationconstructs, for example larger deformity or trauma cases. Additionally,the integral double spinal rod 30 of the present example may be usedwith an adjacent rod during the primary surgery or implanted with theanticipation of adjacent level surgery in the future. The second rod 10may have any cross-sectional shape, and primarily functions to providestability and rigidity to the construct, however the second rod 10 mayalso be used as an attachment point for additional hardware or forbending, etc.

It will be appreciated that an embodiment of the dual rod construct maycomprise a combination of the elements described in the embodiments ofFIGS. 1-6. For example, in one exemplary embodiment, a spinal fixationconstruct 2 comprises a first spinal rod 8; a second spinal rod 10generally parallel to the first rod; a cephalad arm 12 connecting thefirst and second rods 8, 10 and integrally formed with the first andsecond rods 8, 10; and a caudal arm 12 connecting the first and secondrods 8, 10 and integrally formed with the first and second rods 8, 10.The first rod 8 may be generally cylindrical in shape. In someembodiments, the first rod 8 may be uniform in diameter from thecephalad to the caudal arm 12. In some embodiments, the first and secondrods 8, 10 may be of uniform thickness.

The construct 2 may further comprise a rod extension 28 extendinglongitudinally from the cephalad end, from the caudal end, or from boththe cephalad and caudal ends. The construct 2 may further comprise a rodconnector 38 with a rod seat 40 sized and configured to receive aportion of a third spinal rod (not shown). In some embodiments, the rodconnector 38 may be aligned with the first rod. In other embodiments,the rod connector 38 may be aligned with the second rod. And, in stillfurther embodiments, the rod connector 38 may be offset from the firstand second rods.

In some embodiments, the construct comprises a rod connector 38 at thecephalad end. In other embodiments, the construct comprises a rodconnector 38 at the caudal end. In still further embodiments, theconstruct comprises a rod connector 38 at both the cephalad and caudalends. In one embodiment, the rod seat 40 is generally parallel with thefirst spinal rod. In some embodiments the rod connector 38 is formedintegrally with the spinal fixation construct. In some embodiments, therod connector 38 is top-loading. In other embodiments, the rod connector38 is side loading. The rod connector 38 may comprise a tulip.Alternatively, the rod connector 38 may comprise a closed head.

The construct may further comprise a plurality of bone anchors 6 withupstanding arms defining a rod channel 22 dimensioned to accommodate thefirst rod. The bone anchors 6 may be pedicle screws. In someembodiments, the pedicle screws may be polyaxial. Additionally, thefirst rod 8 should be of sufficient length between the cephalad andcaudal arms 12 to accommodate a plurality of bone anchors 6. Further,the distance between the first and second rods 8, 10 should besufficient to allow the first rod 8 to be seated in the rod channel 22.When the first rod 8 is seated in the rod channel 22, the rod 8 may besecured with a plurality of locking screws (not shown). In eachembodiment, the dual spinal rod 2 is constructed entirely from a rigid,non-absorbable biocompatible material.

Although each of the embodiments depicted in FIGS. 1-6 shows the dualrod 2 engaging five bone anchors 6, it will be appreciated that theactual number of bone anchors 6 will vary according to the surgicalprocedure, the number of levels involved, and the preferences of thesurgeon. Moreover, it will be appreciated that the construct 2 may beplaced such that the second rod is located medially or laterallyrelative to the first rod and bone anchors 6. The position of the secondrod 10 may depend upon the surgical procedure, preference of thesurgeon, or requirements of a patient's anatomy.

The foregoing description illustrates and describes the processes,machines, manufactures, compositions of matter, and other teachings ofthe present disclosure. Additionally, the disclosure shows and describesonly certain embodiments of the processes, machines, manufactures,compositions of matter, and other teachings disclosed, but, as mentionedabove, it is to be understood that the teachings of the presentdisclosure are capable of use in various other combinations,modifications, and environments and is capable of changes ormodifications within the scope of the teachings as expressed herein,commensurate with the skill and/or knowledge of a person having ordinaryskill in the relevant art. The embodiments described hereinabove arefurther intended to explain certain best modes known of practicing theprocesses, machines, manufactures, compositions of matter, and otherteachings of the present disclosure and to enable others skilled in theart to utilize the teachings of the present disclosure in such, orother, embodiments and with the various modifications required by theparticular applications or uses. Accordingly, the processes, machines,manufactures, compositions of matter, and other teachings of the presentdisclosure are not intended to limit the exact embodiments and examplesdisclosed herein. Any section headings herein are provided only forconsistency with the suggestions of 37 C.F.R. § 1.77 and related laws orotherwise to provide organizational queues. These headings shall notlimit or characterize the invention(s) set forth herein.

The following is claimed:
 1. A spinal fixation construct comprising: afirst spinal rod; a second spinal rod generally parallel to the firstrod; a cephalad arm connecting the first and second rods and integrallyformed with the first and second rods; and a caudal arm connecting thefirst and second rods and integrally formed with the first and secondrods, and a rod connector with a rod seat sized and configured toreceive a portion of a third spinal rod, wherein the rod connectorextends away from the first spinal rod in a direction orthogonal to thefirst spinal rod and the caudal arm, wherein the rod connector isintegral to the spinal rod fixation system with the rod seat integrallyformed with and in a fixed alignment position with respect to the firstspinal rod.
 2. The spinal rod fixation construct of claim 1, wherein thefirst rod is generally cylindrical in shape.
 3. The spinal rod fixationconstruct of claim 1, wherein the first rod is generally cylindrical inshape and generally uniform in diameter.
 4. The spinal rod fixationconstruct of claim 1, wherein the first and second rods are of uniformthickness between the cephalad arm and the caudal arm.
 5. The spinal rodfixation construct of claim 1, wherein the first rod comprises a rodextension extending longitudinally from the first rod.
 6. The spinal rodfixation construct of claim 1, wherein the rod seat is generallyparallel with the first spinal rod.
 7. The spinal rod fixation constructof claim 1, constructed of a non-absorbable biocompatible material. 8.The spinal rod fixation construct of claim 1, comprising a plurality ofbone anchors with upstanding arms defining a rod channel, wherein saidrod channel is dimensioned to accommodate the first rod.
 9. The spinalrod fixation construct of claim 8, wherein the first rod is ofsufficient length between the cephalad arm and the caudal arm toaccommodate said plurality of bone anchors.
 10. The spinal rod fixationconstruct of claim 8, wherein the first rod is a lateral distance fromthe second rod, and wherein said lateral distance is sufficient to allowthe first rod to be seated in the rod channel.
 11. The spinal rodfixation construct of claim 8, wherein the first rod is seated withinthe rod channel.
 12. A spinal rod fixation construct comprising a dualrod formed as a single unit, a plurality of bone anchors with upstandingarms defining a rod channel, and a plurality of lock screws, wherein thedual rod formed as a single unit comprises: a first spinal rod; a secondspinal rod generally parallel to the first spinal rod; a cephalad armconnecting the first and second spinal rods and integrally formed withthe first and second spinal rods; a caudal arm connecting the first andsecond spinal rods and integrally formed with the first and secondspinal rods; a first rod connector with a first rod seat sized andconfigured to receive a portion of a third rod, wherein the first rodconnector is secured to and extends orthogonally away from both thefirst spinal rod and the cephalad arm in a direction opposite from theplurality of bone anchors, wherein the first rod connector is integrallyformed with the dual rod with the first rod seat in a fixed alignmentposition with respect to the first spinal rod; and a second rodconnector with a second rod seat sized and configured to receive aportion of a third rod, wherein the second rod connector is secured toand extends orthogonally away from both the first spinal rod and thecaudal arm in a direction opposite from the plurality of bone anchors,wherein the second rod connector is integrally formed with the dual rodwith the second rod seat in a fixed alignment position with respect tothe first spinal rod.
 13. The spinal rod fixation construct of claim 12,wherein the system further comprises an extension rod extendinglongitudinally from the dual rod.
 14. The spinal rod fixation constructof claim 12, wherein the first rod seat and second rod seat aregenerally parallel with the dual rod.
 15. The spinal rod fixationconstruct of claim 12, constructed of a non-absorbable biocompatiblematerial.
 16. A dual spinal rod for fixing the relative position of afirst vertebra and a second vertebra, the dual spinal rod comprising: afirst elongate member of generally cylindrical shape having a firstcephalad end and a first caudal end, the first elongate member being ofa diameter suitable to be seated within a rod channel of a pediclescrew, and being of a length sufficient to connect two adjacentvertebrae; a second elongate member roughly parallel to the firstelongate member and having a second cephalad end and a second caudalend; a cephalad lateral portion connecting the first cephalad end to thesecond cephalad end; a caudal lateral portion connecting the firstcaudal end to the second caudal end and roughly parallel to the cephaladlateral portion; and a first rod connector with a first rod seat sizedand configured to receive a portion of a third rod, with the first rodseat integrally formed at a fixed position at the dual spinal rod, andwherein the first rod connector extends orthogonally away from the firstelongate member and from the cephalad lateral portion; wherein the dualspinal rod is constructed entirely and integrally from a rigid,non-absorbable biocompatible material.
 17. The dual spinal rod of claim16, further comprising: a second rod connector with a second rod seat,with the second rod seat integrally formed at a fixed position at thedual spinal rod, and wherein the second rod connector extendsorthogonally away from the first elongate member and from the caudallateral portion.
 18. The dual spinal rod of claim 17, wherein the firstrod seat and second rod seat are aligned with each other and aregenerally parallel to the first elongate member.
 19. The dual spinal rodof claim 17, wherein the first rod connector and second rod connectorare top-loading.